Some 13,000 migrants have gathered along the Turkish-Greek border after Turkey's president threatened to allow some of the many refugees in the country cross into Europe, the UN said Saturday.
"Thousands of migrants, including families with young children, are passing a cold night along the border between Turkey and Greece," the International Organization for Migration said in a statement, adding that its staff had observed "at least 13,000 people gathered along the 212-kilometre (125-mile) long border."
Greek police clashed on Saturday with thousands of migrants who were already gathering on the border to try to enter Europe, while Turkey and Russia, which back opposing forces in the Syria conflict, held high-level talks to try to defuse tensions.
>> Europe 'lacks leverage' over Turkey amid Erdogan migrant threat
Turkey's President Recep Tayyip Erdogan on Saturday vowed to allow migrants to travel on to Europe from Turkey which he said can no longer handle new waves of people fleeing war-torn Syria. It already hosts 3.6 million Syrian refugees.
The comments were his first after Turkish 34 troops were killed since Thursday in the northern Syria province of Idlib where Moscow-backed Syrian regime forces are battling to retake the last rebel holdout area.
"What did we do yesterday (Friday)? We opened the doors," Erdogan said in Istanbul. "We will not close those doors ...Why? Because the European Union should keep its promises."
He was referring to a 2016 deal with the European Union to stop refugee flows in exchange for billions of euros in aid.
In Athens, Greek Prime Minister Kyriakos Mitsotakis held an emergency meeting to discuss tensions on the border with Turkey.
The Turkish leader said 18,000 migrants have amassed on the Turkish borders with Europe since Friday, adding that the number could reach as many as 30,000 on Saturday.
Thousands of migrants who remained stuck on the Turkish-Greek border were in skirmishes with Greek police on Saturday who fired tear gas to push them back, according to AFP photographer in the western province of Edirne.
The migrants massed at the Pazarkule border crossing responded by hurling stones at the police.
'Violations of our borders'
In 2015, Greece became the main EU entry point for one million migrants, most of them refugees fleeing the Syrian civil war. The pressure to cope with the influx split the European Union.
"Greece yesterday came under an organised, mass, illegal attack... a violation of our borders and endured it," government spokesman Stelios Petsas said Saturday after the emergency meeting with Mitsotakis.
"We averted more than 4,000 attempts of illegal entrance to our land borders."
A Greek police source said security forces fired tear gas Saturday morning against migrants massing on the Turkish side because the migrants had set fires and opened holes in the border fences.
Armed policemen and soldiers are patrolling the Evros river shores -- a common crossing point -- and are warning with loudspeakers not to enter Greek territory.
Greek authorities were also using drones to monitor the migrants moves.
Defense Minister Nikos Panagiotopoulos told Skai television the situation was under control
"I believe that the borders have been protected," he said.
According to Hellenic Coast Guard, from early Friday to early Saturday 180 migrants reached the islands of Eastern Aegean, Lesbos and Samos in sea crossings.
The UN said nearly a million people -- half of them children -- have been displaced in the bitter cold by the fighting in northwest Syria since December.
'Pay a price'
Turkey said that Turkish forces destroyed a "chemical warfare facility," just south of Aleppo, in retaliation its soldiers were killed by Syrian regime fire in Idlib.
"As of last night, we blew up a depot housing seven chemical products," Erdogan said. "We would not want things to reach this point but as they force us to do this, they will pay a price."
But the Syrian Observatory for Human Rights, which relies on sources inside the war-torn country, said that Turkey instead hit a military airport in eastern Aleppo, where the monitoring group says there are no chemical weapons.
Thirty-three Turkish soldiers were killed in an air strike by Russian-backed Syrian regime forces in the Idlib on Thursday, the biggest Turkish military loss on the battlefield in recent years. A 34th Turkish soldier has since died.
The latest incident has raised further tensions between Ankara and Moscow, whose relationship has been tested by violations of a 2018 deal to prevent a regime offensive on Idlib.
As part of the agreement, Ankara set up 12 observation posts in the province but Syrian President Bashar al-Assad's forces -- backed by Russian air power -- have pressed on with a relentless campaign to take back the remaining chunks of the territory.
On Friday, Erdogan spoke by phone with his Russian counterpart, Vladimir Putin, in a bid to scale down the tensions, with the Kremlin saying the two expressed "serious concern" about the situation.
Erdogan may travel next week to Moscow for talks, according to the Kremlin.
Despite being on opposite ends of the war, Turkey, which backs several rebel groups in Syria, and key regime ally Russia are trying to find a political solution.
The United States and the United Nations have called for an end to the Syrian offensive in Idlib and the deadly flare-up raising fresh concerns for civilians caught up in the escalation of the eight-year civil war.
(FRANCE 24 with AFP)